By Dan Abbott, Reef Check California Central Coast Manager
Every year, the Western Society of Naturalists holds an important conference largely focused on west coast nearshore marine ecosystems. This year was the conference's 100th anniversary and Reef Check attended in force! Reef Check staff from north, central and southern California traveled to Ensenada, Mexico to present data collected by citizen science divers to the larger scientific community.
Tristin McHugh presented data on the status of North Coast fish populations in the five years after the onset of Sea Star Wasting Disease and the phase shift of that region's kelp forest to urchin barrens. Fish populations have varied by location and by species but interestingly, many species appeared to undergo a big increase around 2016 before dropping back down to historic levels this year. The cause of this apparent spike in populations is so far a mystery and Reef Check is going to be studying this phenomenon going forward.
Dan Abbott presented data collected by Reef Check's team of volunteer divers on the varied response of kelp forest ecosystems to environmental stressors that have occurred off the California coast the last few years, including the loss of sea stars, marine heatwaves, and the dramatic increase in the purple urchin population. Responses in kelp forests to these events have varied from the North Coast where there has been an almost complete loss of kelp, to Big Sur where there has been little change and kelp forests remain entirely intact. Along the Monterey Peninsula and in Carmel Bay responses were mixed with some sites becoming urchin barrens, some sites remaining kelp forests, and some sites becoming a mosaic of barren and forest areas. Most interesting are sites along the outer peninsula that went from being a forest of giant kelp, to a complete urchin barren for a number of years, back to a kelp forest but now dominated by the canopy-forming bull kelp.
Selena McMillian gave a talk on how monitoring programs have to adapt their protocols to capture the nature of a changing ocean. Examples she gave included Reef Check expanding the list of species it counts by adding previously rarely seen organisms that have become much more common either due to range expansions or species invasions. Selena also talked about how protocols that accurately characterize an ecosystem in one area may not accurately characterize a similar ecosystem in a different area. In particular, she mentioned kelp forests in the southernmost part of the state where some kelps exhibit different growth forms or occur deeper than in the rest of the state, requiring Reef Check to adapt its protocols so that these areas are recorded as the lush areas of kelp that they are.
In addition to presenting data collected by citizen scientists, Reef Check's staff was able to engage and collaborate with other marine scientists to further our understanding of California's kelp forests and the changes these ecosystems are experiencing.
Tristin, Selena and Dan during their presentations